Heat-shrinkable thermoplastics are known to be useful as flexible packaging materials for vacuum packaging various foodstuffs, including meat. Such plastic materials, however, while generally suitable for packaging meat, understandably have difficulties in successfully packaging sharp or bony products. For example, attempts to package bone-in primal cuts of meat usually result in an unsatisfactorily large number of bag failures due to bone punctures. The use of cushioning materials such as paper, paper laminates, wax impregnated cloth, and various types of plastic inserts have proved to be less than totally satisfactory in solving the problem. The preparation of special cuts of meat or close bone trim with removal of protruding bones has also been attempted. However, this is at best only a limited solution to the problem since it does not offer the positive protection necessary for a wide variety of commercial bone-in types of meat. Furthermore, removal of the bone is a relatively expensive and time-consuming procedure.
The use of heat-shrinkable bags having one or two patches adhered thereto has recently become a commercially-preferred manner of packaging a number of bone-in meat products. However, even the bags having two patches thereon leave "uncovered regions" (i.e., regions of the bag which are not covered by the patch, also herein referred to as "bald regions") which are more vulnerable to puncture because they do not have a patch adhered thereover.
It has been found that in the packaging of several bone-in meat products, for example with a patch bag containing a pair of bone-in pork loins, the bones cause bag failures to occur if the patch bag has one or more uncovered regions along the length of the bag, and/or along the bottom of the bag. An undesirable level of bag failures occur when these uncovered regions contact the bone-in meat product.
Providing a much-oversized bag can be used to reduce the number of punctures, as the pork loins can be placed in the center of the bag so that the uncovered regions are present on "dog-ears" emanating from the package. However, this solution to the problem is not entirely satisfactory, for several reasons. First, there is the inefficiency of wasted package due to the excessive bag size required to keep the uncovered areas away from the pork loins. Second, the dog-ears running the length of the package provide an aesthetically less-attractive package. Third, the loins must be carefully placed in the center of the bag, to avoid bone contact with the uncovered areas. Fourth, the meat has the potential to slide around inside the oversized bag, resulting in the potential for the bone to contact uncovered regions, thus increasing the potential for package failure.
It would be desirable to have a patch bag in which the product cannot contact uncovered regions across the bottom of an end-seal bag, in order to reduce or eliminate the number of bone punctures through the bag.
However, making, for example, an end-seal patch bag in which the patch extends to the bottom edge of the bag, requires that the bottom seal be through the patch as well as the bag, assuming that the patch is applied to the bag tubing before the bottom seal is produced. Sealing by passing heat through one or more patches is undesirable because such seals are not as strong as seals made through the bag alone. Furthermore, seals made through the patches and bags are subject to burn through due to the need to conduct heat completely through the patch material. Thus, it is desirable to provide a patch bag in which the product contacts only covered regions of the bag, or contacts less uncovered region, relative to patch bags in which the seal is a substantial distance from the edge of the patch.